Just because the season is brand new doesn't mean players and coaches have forgotten old grudge matches.
The Jets and Patriots have turned every matchup into a trash talking show, and any Steelers vs. Ravens game is guaranteed to be a blood bath.
We now have personal grudge matches between players on Twitter too (Chad Johnson and Shawne Merriman).
Revenge is a common theme in every sport, but given how competitive and thrilling the NFL has become, there is never a dull moment in any game.
Take the Titans and Texans for example, who collided with each other for a bottom-of-the-division game last season. The game went from football to boxing after Andre Johnson and Cortland Finnegan duked it out.
You can bet every NFL team has circled several games on the schedule as a reminder to deliver the final punch, if you will.
Which players and coaches are still bitter about the past and itching for redemption in 2011? Buckle your chinstrap, we're about to explode out of the tunnel.
Jacksonville had a chance to win the AFC South at season's end because of a miraculous hail mary victory in Week 10 against Houston.
Many people think Houston is the better team, so this year, if they can manage to win the critical games against the division, a playoff spot is possible.
For now, the Houston secondary needs to bury the embarrassment of letting David Garrard abuse them.
Neither of these guys are certain of where they'll play in 2011, but they hope to clash in a Sunday matchup.
For one reason or another, Johnson and Merriman had a Twitter battle around a month ago, as Johnson accused Merriman of producing only due to steroids. Merriman insulted Johnson's abilities as well.
All of this only proves that Twitter and social media usually make things worse for athletes, but a good fight is something a sports fan won't turn away from.
Ray Lewis rung Dustin Keller's bell on a ball across the middle during Week 1.
If Keller can remember that hit, he'll want to make some kind of nice catch against Lewis when they square off in Week 4 this year.
When the Chiefs and Patriots square off on Monday Night Football this season, Tom Brady will attempt to beat his former backup.
Cassel landed a gig as high-paid starter after showing success with the Patriots in 2008, the year Brady tore his ACL.
Both teams have better offenses than defenses, and with the way Todd Haley likes to throw the ball, we could see a high scorer. It will be a good one.
There's also the added factor of Romeo Crennel as Kansas City's defensive coordinator, formerly with New England.
It's Jim Harbaugh's first year in the league as the head coach of the 49ers. His brother John would like nothing more than for Ray Lewis to punish Alex Smith.
Jim is already having a tough time, considering Frank Gore is holding out. This brotherly rivalry is one of intelligence, and it can potentially get sweeter if the 49ers land Andrew Luck in next year's draft.
These twin brothers make fun of each other all year long in the media, and now, they'll face one another again.
Rex got the best of him while he was with the Browns in 2010, but Rob is now the defensive coordinator with the Cowboys. Conveniently, New York hosts Dallas in Week 1.
Both men have high hopes for their teams, but it would be a blow to Rex if his own brother beat him so early in the season.
Naturally, because the Vikings and Packers are huge rivals, McNabb will be expected to beat them. Vikings fans are looking to forget the misery of Brett Favre in 2010.
McNabb will play in a division that now contends with the difficulty of the NFC East, and Green Bay will be his biggest task.
Donavan McNabb was just dealt to Minnesota, and conveniently, he'll square off against Mike Shanahan in Week 16.
McNabb should feel disrespected for being benched in favor of lowly Rex Grossman last year. D-Nabb is the All-Pro quarterback, and the guy who's conquered that division several times.
Now, he has a chance to show Shanahan that there's a such thing as a bad decision for a coach who has won two Super Bowls.
Kevin Kolb has long awaited his departure from Philadelphia, and now it's nearly final in the form of a trade to the Arizona Cardinals.
Both teams meet in 2011, and there isn't much else to say besides the fact that Kolb will finally get to prove himself. He has warmed the bench for too long.
Jay Cutler received a lot of criticism while in Denver, and the Bears paid a steep price to acquire him. Currently, Cutler has the edge after going to the NFC Championship last year.
Broncos fans didn't like Cutler, and he'll hear it from them after leaving the game against Green Bay and not returning.
He's not one to talk trash, but in all likelihood, the Bears will beat Tim Tebow's Broncos, and Cutler's heart will be filled with joy.
When you think about who the Packers lost against in 2010, the Lions wouldn't be a likely candidate. Detroit beat Green Bay 7-3, but the Packers didn't have star quarterback Aaron Rodgers.
The Lions are getting exponentially better, but Rodgers must show them that last year's victory was a mirage. Right now, Rodgers is the league's best player, and he will make Detroit remember that.
One of the games Tony Romo got to play in 2010 was against Washington. When Romo thought he'd thrown the winning touchdown on the final play in Week 1, Cowboys LT Alex Barron had it rescinded for a blatant holding penalty.
The game was over on that play, and the Redskins won. Tony Romo will have a healthy and improved offensive line against a weaker Redskins team. He's looking for two wins against them in 2011.
The matchup is mediocre, but it's possible that both teams will decide who wins the NFC West again.
Sam Bradford is the intriguing factor here because he is no longer a rookie, and he played extremely well for the Rams last year.
The Seahawks no longer have veteran Matt Hasselbeck, but they've added Sidney Rice. Bradford will be looking to head to the postseason and continue taking substantial steps forward.
To Tom Coughlin's chagrin, the dreadful Cowboys season made its "turn around" against the Giants in 2010.
Jason Garrett had Dallas' offense putting on a show against New York, and his strict nature eventually landed him the head coaching job.
Coughlin's face that day looked a little more angry, and he'll be ready to lasso up the Cowboys in 2011.
The Colts' defense wasted a 400-yard, three-touchdown day by Peyton Manning because they chose Week 1 to be Arian Foster's coming out party. Foster ran for 231 yards that day.
Indianapolis' run defense has been a joke over the past couple seasons, and it's time to fix it. The Colts meet the Texans in Week 1 again, and Arian Foster needs to be slowed down.
Before a scheduled meeting against the Jets, coach Bill Belichick asked his players not to give in to Ryan's antics and media attention. Welker proceeded to tell the media of how his team planned to "march" like "foot soldiers" in the game on Sunday.
He was benched for the first quarter of that playoff game, and the Pats lost. Welker will be the one looking for revenge.
It's a classic rivalry that fans outside of Cleveland and Pittsburgh don't acknowledge much.
Regardless, a win for the Browns can make their season depending on how poorly they play, while a loss for the Steelers can prevent a playoff birth. This happened in 2009 for both teams.
Now, Colt McCoy has more to prove than anyone, and he'll have to beat the Steelers in the last month of the season.
There's a chance that both of these teams meet again in the playoffs. For the second year in a row, Sanchez fell short in the AFC Championship, and although the game appeared close, the Steelers defended him nicely.
Sanchez still proves to be a poor decision maker, and being that both teams will likely make the playoffs, he'll be thinking about this past January again.
The word revenge can't be emphasized enough in this game. These teams met in the Super Bowl, and the Giants completed the most unlikely victory in Super Bowl history.
There's no way Tom Brady and Bill Belichick won't be thinking about what could have been when they went into the championship at 18-0.
Now, Eli Manning is a better quarterback, and he'll look to get another win against Brady.
The Chiefs stunned the Chargers on Monday Night Football in Week 1, but San Diego shut them out later in the season.
Ultimately, the Chiefs moved on to play in January, as Norv Turner's history of slow starts continued and he was left to sit at home. The Chiefs are on the rise, while San Diego looks to get Ryan Mathews going.
Both of these teams are balanced and will likely battle for the division crown. Turner should be thinking about avoiding the hot seat this season.
Yes, this is absolutely a rivalry, but Ryan Clark thinks otherwise. He told Ray Rice that the Steelers aren't rivals with the Ravens simply because "Baltimore doesn't beat them enough."
It's insulting, but guys like Ray Lewis are waiting for the grudge match. The fireworks are going to be spectacular.
The rivalry between these teams is frequently found on this list, but Woodley made things personal with Flacco.
Woodley said Flacco's Ravens won't reach the Super Bowl in his (Flacco's) lifetime. Both guys are young, and figure to be playing against each other for a long time. This will be great to watch.
The Falcons emerged as an NFC powerhouse a year after the Saints won the Super Bowl. Atlanta had the best record in the NFC last season, but New Orleans handed them one loss.
Both games between these division foes were decided by three points and in the fourth quarter or overtime.
The Jets didn't score a touchdown against the Ravens when they squared off last season.
Mark Sanchez didn't have any fun against a blitzing Ray Lewis, and he needs to prove himself against great defenses. Rex Ryan will be facing his former team, too.
The Bears surprised the rest of the league with Jay Cutler at the helm in 2010. This rivalry is a classic, and both teams have years of hate built up.
Cutler failed miserably against Green Bay in the playoffs, so he'll be the guy looking to beat the champs in 2011. Good luck, Jay.
The Falcons beat the Buccaneers 27-21 and 28-24 in 2010. The Bucs missed the playoffs, but had they won both of these games, you could've counted them in.
Josh Freeman was a big surprise in clutch situations, and there's no reason for that not to continue in 2011. He wants to beat the powerhouse that is the Falcons.
The Raiders went 6-0 against the AFC West in 2010 but missed the playoffs. In addition, because of the way San Diego usually starts out the season, this Week 17 matchup could very possibly have playoff implications for both teams.
It's not hard to imagine Philip Rivers trying to grind San Diego to 10-6 for the division title or Oakland pushing for 9-7 and a wild-card spot.
The revenge factor sits with the Chargers, since they lost both meetings in 2010.
Any matchup in the NFC East is worth watching, but the Eagles and Giants took it to a whole new level in 2010.
The Eagles won both games in the 2010 regular season, and you can bet DeSean Jackson is still dancing in Tom Coughlin's head. The Giants must beat the Eagles this year.
The Eagles completed the second "Miracle at the Meadowlands" in 2010. Philadelphia scored 28 unanswered points, but no touchdown was more spectacular than the final play, DeSean Jackson's 65-yard punt return.
After he scored, Tom Coughlin had a meltdown and nearly choked punter Matt Dodge. You can bet Coughlin will kick the ball out of bounds if presented with the same situation, but he'd probably rather punt to Jackson with an insurmountable lead.
He'll need to beat Philadelphia to win the division.
The media coverage for this game will be epic. Michael Vick returns to Atlanta in a matchup against his former team. He was actually hurt when both teams met last year.
We don't know what to expect from the Atlanta fans, but Vick might be poised for a special performance. Both teams are among NFC supremacy, and even though it's Week 2, the game matters a lot.
This matchup holds the chances of both teams squaring off as the best in their respective conferences. For several weeks in 2010, Las Vegas odds had the Eagles and Pats meeting in the Super Bowl.
That's entirely possible in 2011, especially if Tom Brady and Michael Vick repeat their performances of yesteryear.
It's a rematch of the Super Bowl teams from two years prior. Indy's schedule looks daunting, so this would be a big win for Peyton Manning and company.
Manning hasn't likely forgotten that game from last February, and he'd like to redeem himself. It should be a barn burner, as neither team has a reputable defense.
Lovie Smith has all of the incentive for revenge in this case. He told his team last season that one of his priorities when coming to Chicago was "beat the Packers."
He faltered to McCarthy's masterful coaching in 2010, and now, Smith still has less talent to work with. Smith has work to do, and his Cover 2 defense must stop Aaron Rodgers.
Rex Ryan's mouth never closes, while Bill Belichick's book of strategy constantly gets thicker. Because of the prestige of both coaches, this rivalry has gotten huge.
The division title will be within reach for both teams all season, and it's up to the coaches to outsmart each other.
Right now, Belichick is seeking revenge from last year's playoffs. He has the better team.
Bart Scott is officially a target. He backed up Rex Ryan's guaranteed victory against the Pats in the playoffs, and then added to it with a little more trash talk.
The buildup for these divisional games can't be explained, but Scott can't wait, and neither can we.
The Titans and Texans didn't finish well in 2010, but their games stayed competitive because Cortland Finnegan ran his mouth.
Finnegan received the beating of his life by Andre Johnson after a play was over.
Knowing the way Finnegan carries himself, he will likely talk trash again to the NFL's top receiver, but this time, Johnson will just beat him with pure football skill.
These two greats define an era. To signify how important of a rivalry this is in the NFL, the Colts and Patriots are the only two non-divisional teams to meet every season.
Brady won last year's game by a hair and also took down the MVP trophy. Manning wants revenge, and with a healthy offense again, he can surely get it.
James Harrison has been fined hundreds of thousands of dollars in the past couple seasons for illegal hits. He's upset about the penalties, and feels that Roger Goodell is singling him out.
As seen in his comments recently, Harrison isn't afraid to speak his mind, but will he go so far as to miss games this season for his ferocious play? Will Goodell "abuse his power" again?
It will be interesting, but regardless, Harrison wants the last laugh.
These two teams enjoy trading blows with each other.
Both Bill Belichick and Rex Ryan have respect for one another, but several Jets players seem to think of Tom Brady as disrespectful and cocky.
The Jets beat the Pats in January, and the rivalry is steaming. In the words of Bart Scott, "CAN'T WAIT!"
This rivalry is without a doubt the most physical in the league.
Both defenses are loaded with savvy veterans, and several players from both teams have expressed their discontent for each other already.
Mike Tomlin and John Harbaugh know that the division will likely be decided in late December.
Baltimore needs to get over the hump because after holding a big lead against Pittsburgh in the Divisional Round last year, they blew it.